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power: max17042_battery: add HEALTH and TEMP_* properties support
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This patch adds the support for following battery properties
to max17042 fuel gauge driver.

POWER_SUPPLY_PROP_TEMP_ALERT_MIN
POWER_SUPPLY_PROP_TEMP_ALERT_MAX
POWER_SUPPLY_PROP_TEMP_MIN
POWER_SUPPLY_PROP_TEMP_MAX
POWER_SUPPLY_PROP_HEALTH

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
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Ramakrishna Pallala authored and Sebastian Reichel committed May 23, 2015
1 parent 4aeae9c commit edd4ab0
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Showing 2 changed files with 183 additions and 11 deletions.
190 changes: 179 additions & 11 deletions drivers/power/max17042_battery.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -63,6 +63,8 @@
#define dP_ACC_100 0x1900
#define dP_ACC_200 0x3200

#define MAX17042_VMAX_TOLERANCE 50 /* 50 mV */

struct max17042_chip {
struct i2c_client *client;
struct regmap *regmap;
Expand All @@ -85,10 +87,94 @@ static enum power_supply_property max17042_battery_props[] = {
POWER_SUPPLY_PROP_CHARGE_FULL,
POWER_SUPPLY_PROP_CHARGE_COUNTER,
POWER_SUPPLY_PROP_TEMP,
POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
POWER_SUPPLY_PROP_TEMP_MIN,
POWER_SUPPLY_PROP_TEMP_MAX,
POWER_SUPPLY_PROP_HEALTH,
POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_CURRENT_AVG,
};

static int max17042_get_temperature(struct max17042_chip *chip, int *temp)
{
int ret;
u32 data;
struct regmap *map = chip->regmap;

ret = regmap_read(map, MAX17042_TEMP, &data);
if (ret < 0)
return ret;

*temp = data;
/* The value is signed. */
if (*temp & 0x8000) {
*temp = (0x7fff & ~*temp) + 1;
*temp *= -1;
}

/* The value is converted into deci-centigrade scale */
/* Units of LSB = 1 / 256 degree Celsius */
*temp = *temp * 10 / 256;
return 0;
}

static int max17042_get_battery_health(struct max17042_chip *chip, int *health)
{
int temp, vavg, vbatt, ret;
u32 val;

ret = regmap_read(chip->regmap, MAX17042_AvgVCELL, &val);
if (ret < 0)
goto health_error;

/* bits [0-3] unused */
vavg = val * 625 / 8;
/* Convert to millivolts */
vavg /= 1000;

ret = regmap_read(chip->regmap, MAX17042_VCELL, &val);
if (ret < 0)
goto health_error;

/* bits [0-3] unused */
vbatt = val * 625 / 8;
/* Convert to millivolts */
vbatt /= 1000;

if (vavg < chip->pdata->vmin) {
*health = POWER_SUPPLY_HEALTH_DEAD;
goto out;
}

if (vbatt > chip->pdata->vmax + MAX17042_VMAX_TOLERANCE) {
*health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
goto out;
}

ret = max17042_get_temperature(chip, &temp);
if (ret < 0)
goto health_error;

if (temp <= chip->pdata->temp_min) {
*health = POWER_SUPPLY_HEALTH_COLD;
goto out;
}

if (temp >= chip->pdata->temp_max) {
*health = POWER_SUPPLY_HEALTH_OVERHEAT;
goto out;
}

*health = POWER_SUPPLY_HEALTH_GOOD;

out:
return 0;

health_error:
return ret;
}

static int max17042_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
Expand Down Expand Up @@ -181,19 +267,34 @@ static int max17042_get_property(struct power_supply *psy,
val->intval = data * 1000 / 2;
break;
case POWER_SUPPLY_PROP_TEMP:
ret = regmap_read(map, MAX17042_TEMP, &data);
ret = max17042_get_temperature(chip, &val->intval);
if (ret < 0)
return ret;
break;
case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
ret = regmap_read(map, MAX17042_TALRT_Th, &data);
if (ret < 0)
return ret;
/* LSB is Alert Minimum. In deci-centigrade */
val->intval = (data & 0xff) * 10;
break;
case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
ret = regmap_read(map, MAX17042_TALRT_Th, &data);
if (ret < 0)
return ret;
/* MSB is Alert Maximum. In deci-centigrade */
val->intval = (data >> 8) * 10;
break;
case POWER_SUPPLY_PROP_TEMP_MIN:
val->intval = chip->pdata->temp_min;
break;
case POWER_SUPPLY_PROP_TEMP_MAX:
val->intval = chip->pdata->temp_max;
break;
case POWER_SUPPLY_PROP_HEALTH:
ret = max17042_get_battery_health(chip, &val->intval);
if (ret < 0)
return ret;

val->intval = data;
/* The value is signed. */
if (val->intval & 0x8000) {
val->intval = (0x7fff & ~val->intval) + 1;
val->intval *= -1;
}
/* The value is converted into deci-centigrade scale */
/* Units of LSB = 1 / 256 degree Celsius */
val->intval = val->intval * 10 / 256;
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
if (chip->pdata->enable_current_sense) {
Expand Down Expand Up @@ -237,6 +338,69 @@ static int max17042_get_property(struct power_supply *psy,
return 0;
}

static int max17042_set_property(struct power_supply *psy,
enum power_supply_property psp,
const union power_supply_propval *val)
{
struct max17042_chip *chip = power_supply_get_drvdata(psy);
struct regmap *map = chip->regmap;
int ret = 0;
u32 data;
int8_t temp;

switch (psp) {
case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
ret = regmap_read(map, MAX17042_TALRT_Th, &data);
if (ret < 0)
return ret;

/* Input in deci-centigrade, convert to centigrade */
temp = val->intval / 10;
/* force min < max */
if (temp >= (int8_t)(data >> 8))
temp = (int8_t)(data >> 8) - 1;
/* Write both MAX and MIN ALERT */
data = (data & 0xff00) + temp;
ret = regmap_write(map, MAX17042_TALRT_Th, data);
break;
case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
ret = regmap_read(map, MAX17042_TALRT_Th, &data);
if (ret < 0)
return ret;

/* Input in Deci-Centigrade, convert to centigrade */
temp = val->intval / 10;
/* force max > min */
if (temp <= (int8_t)(data & 0xff))
temp = (int8_t)(data & 0xff) + 1;
/* Write both MAX and MIN ALERT */
data = (data & 0xff) + (temp << 8);
ret = regmap_write(map, MAX17042_TALRT_Th, data);
break;
default:
ret = -EINVAL;
}

return ret;
}

static int max17042_property_is_writeable(struct power_supply *psy,
enum power_supply_property psp)
{
int ret;

switch (psp) {
case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
ret = 1;
break;
default:
ret = 0;
}

return ret;
}

static int max17042_write_verify_reg(struct regmap *map, u8 reg, u32 value)
{
int retries = 8;
Expand Down Expand Up @@ -665,6 +829,8 @@ static const struct power_supply_desc max17042_psy_desc = {
.name = "max170xx_battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.get_property = max17042_get_property,
.set_property = max17042_set_property,
.property_is_writeable = max17042_property_is_writeable,
.properties = max17042_battery_props,
.num_properties = ARRAY_SIZE(max17042_battery_props),
};
Expand All @@ -673,6 +839,8 @@ static const struct power_supply_desc max17042_no_current_sense_psy_desc = {
.name = "max170xx_battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.get_property = max17042_get_property,
.set_property = max17042_set_property,
.property_is_writeable = max17042_property_is_writeable,
.properties = max17042_battery_props,
.num_properties = ARRAY_SIZE(max17042_battery_props) - 2,
};
Expand Down
4 changes: 4 additions & 0 deletions include/linux/power/max17042_battery.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -215,6 +215,10 @@ struct max17042_platform_data {
* the datasheet although it can be changed by board designers.
*/
unsigned int r_sns;
int vmin; /* in millivolts */
int vmax; /* in millivolts */
int temp_min; /* in tenths of degree Celsius */
int temp_max; /* in tenths of degree Celsius */
};

#endif /* __MAX17042_BATTERY_H_ */

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